Carbureter.



W. M. FULTON.

CARBURETER.

APPLICATION FILED MAR. 31, I913.

N NN N Witness UNITED STATES PATENT OFFICE.

WESTON M. FULTON, OF KNOXVILLE, TENNESSEE, ASSIGNOR TO THE FULTONCOMPANY, OF KNOXVILLE, TENNESSEE, A CORPORATION OF MAINE.

" cannunn'rnn.

I Specification of Letters Patent.

Patented Dec. 21, 1915.

Application filed March 31, 1913. Serial No. 757,887.

To all whom it may concern Be it known that I, WEs'roN-M. FULTON,

of Knoxville, Tennessee, have invented a" approximately the maximumexplosive effeet may be automatically maintained.

A further object of my invention is to dispense with manual regulationof the fuel supply and thereby relieve the operator of the inconvenienceand annoyance of an act which heretofore has required considerableattention and to economize the use of fuel while at all times securingthe maximum or approximately the maximum amount of energy from theexplosive mixture.

These and other objects will be fully explained in the detaileddescription.

Heretofore carburetors for engines have usually depended on manualadjustments ferregulating the relative quantities of air and vapordelivered by the carbureter. For various reasons manual adjustments areobjectionable. Owing to the varying demands made upon the carbureter bythe engine; adjustments must be frequent. This demands considerableattention and is inconvenient and annoying to the operator. Accurateregulation of the proportions of air and vapor is essential to securethe best working results. Too large proportion of vapor causes! waste offuel and cylinder troubles.

Too small a proportion causes weak explosions and sometimes stopping ofthe engine.

My invention overcomes the above objections and secures the objectsherein stated by providing a carburetor with temperature controlledmeans for automatically regulating the supply of fuel to the carburetor,whereby any predetermined proportion of air and fuel vapor may bemaintained in the explosive mixture delivered by the carbureter.

Heretofore air has been supplied to the carburetor either at variabletemperature or at constant temperature. My invention is applicable toeither case, and in applying my invention I provide a thermosensitiveelement subject both to the temperature of the air entering thecarbureter and also to the variable temperature of the mixture of airand fuel vapor in the carbureter and by means of this element, controlthe supply of fuel to the carbureter. Thus the explosive mixture of airand vapor is made constant in composition by automatically maintaining aconstant difference of temperature between the incoming air and-theoutgoing mixture of air and fuel vapor.

In order that the invention may be readily imderstood, certainmechanical expressions of the inventive idea involved are shown in theaccompanying drawings which are designed merely as illustrations toassist the description of the invention and not as defining the limitsthereof.

In the drawings :Figure 1 is a central, vertical sectional View withinterior parts in elevation showing a carburetor provided with myimprovements. Fig. 2 is a perspective' detail view, and Fig. 3 is'a sideelevational detail view.

Referring to Fig. 1, there is illustrated a carbureter having a floatchamber 1, supplied with liquid fuel through supply pipe 2. An annularfloat 3 maintains the liquid in the chamber 1 at a predetermined levelby controlling the liquid fuel supply entering through pipe 2 by meansof a needle valve 5 connected through securing means. I to the I floatby a lever 6 pivoted at 7. Through the float chamber 1 is an air pas-.sage 8 open to an air supply conduit 9 and vide three tubular castings:a casting 14 ported; and a top casting 16 provided with a flange airinlet connection 17 and a flanged outlet connection 18. The severalsections of castings 14,15 and 16, when assembled, are secured togetherby flanges and bolts in the usual manner. For the purpose of supportingthe thermosensitive elements,

to be described, semi-circular bearings or supports 19, 19 are formed inthe wall of casting 15 and correspondingly shaped caps 20, 20, areformed in the wall of casting 16. In Fig. 1, two suchsupports are shown.I

Referring to Fig. 1, I have shown two similar thermosensitive elements21,22, preferably of the construction shown and described in my U. S.Patents 729,926, 729,- 927 and 760,443. The opposite end walls of eachvessel are non-flexible and are pro- Vided with hubs 23, 24, centrallylocated. Hubs 24 are adapted to fit in supports 19, 19, and are providedwith threaded extensions 25, 25, for receiving fastening nuts 26, 26. Tofacilitate the application of the nuts,

a slot 27 is cut in the threaded end of each.

hub 24. The movable ends of the vessels 21,

' 22 are connected by a rod 28 which is'adapted to be screwed intothreaded sockets in hubs 23,- 23. The connecting rod 28 worksthe airsupply conduit 9, and is provided with annular shoulders 30 betweenwhich is held the forked end of one arm31 of a bell-crank lever, thecompanion arm 32 of which is also forked and pivotally supports thevalve stem 33 carrying needle valve 13. The valve 13 is preferablyprovided with a slender guide pin 34 for centering the valve on itsseat. Lugs 35, Fig. 2, formed on the casting 15 contain a knife-edgepivot 36 which is received in a slotted opening in the elbow of thebell-crank lever and forms an anti-friction fulcrum for thelever. Thearm 31 is provided with knife-edge pivots 37 onwhich bear the forkedends of a springpressed adjusting rod 38. This rod has a shoulder 39against which a spring 40 is pressed by means of a thumb-screw 41 working in a threaded opening in the wall of the casting 15 and bearing onan adjusting plate 42. The spring is preferably housed in a recess 43formed in the wall. Openings 44 and .45 are provided in the casting 16for receiving thermometers when the carbureter is adjusted and areafterward closed by screw plugs 46 and 47 when the adjustment is com- Ipleted.

The casting 16 may be'and sometimes is provided with a spring pressedvalve 48 normally closing a passage between the atmos- 'phere and thespace in the mixing chamber and is adapted to admit air and relieve anymaterial difference of pressure in the mixing chamber and the airconduit which latter is open to the atmosphere.

By reason of the peculiar design of the castings, the parts are readilyassembled. In casting 14, the float 3 and its parts are secured. Casting15 is then placed on casting 14 and secured thereto by clamping bolts49. Bell crank-lever 31, 32 with its valve 13 and adjusting rod 38 arepositioned in casting 15. The two thermostatic elements 21 and 22 havingpreviously been connected by red 28 are placed with their hubs 24resting in the semi-circular bearings 19, 19, and with the portion ofrod 28 between shoulders 30 resting in the forked end of lever arm 31.

cured to section 15 bybolts 49'.

In describing the operation of the carbureter, the parts are assumed tohave been assembled in the manner described and that the discharge endof the same is connected to an internal combustion engine through asuitable connection.

Adjusting the carbureter: The liquid fuel is admitted to the floatchamber 1 and maintained at proper level by float 3 acting on needlevalve 5 which has been properly adjusted for this purpose. The throttlevalve 11 is set partly open and the engine is started, thermometershaving previously been introduced through openings 44 and 45. -Theengine creates a draft of air through conduit 9 in the direction of thearrows, past the spray nozzle 12, throughthe mixing chamber 10 and pastthe throttle valve 11. Thermosensitive element 21 is thus subjected tothe temperature of'the incoming air and thermosensitive element 22 tothe temperature of the mixture of vapor and air in the mixing chamber10. In the act of spraying the volatile liquid fuel into'the current ofair, the vaporizationresulting abstracts heat from the air in a mannerwell understood, and lowers the temperature of the mixture.

The thermosensitive elements 21 and 22 are therefore subjected todifferent temperatures I while the engine is in operation. Thisdifference of temperature between the incom-,

ing. air and the mixture of air and vapor passing. through the mixingchamber,,de-'

pends upon the relative quantity of air and liquid fuel vaporized intothe air and is a measure of the ratio of the quantity of vapor to thatof the air in the mixing chamber. Thereforea gaseous mixture ofpractically any predetermined composition may be maintained in themixing chamber by keep ing a constant difference of temperaturefbes- 1tween the incoming air and the outgoing mixture of air and vapor. It hasheretofore been determined that between certain limiting proportions airand inflammable gases and vapors produce explosive mixtures .which burnwith completecombustion. "It

' ence taken.

is, therefore, only necessary to determine by experiment the differencein temperature- Which'must exist between the incoming air and theout-going mixture for a given explosive combination of air and vapor andthen to maintain as near as practicable this difference of temperatureby means of the thermostatic control device. This is accomplished in thefollowing manner: The engine being in operation, a current of air andvapor passes through the apparatus. Previous tests have indicated forexample that a satisfactory explosive mixture of air and gasolene isobtained when there is a diflerence of about 14 C. between the incomingair and out-going mixture. The temperatures of the incoming air and theair and vapor mixture are noted on the two thermometers above referredto and their differ- Should this difference be less than the oneselected for standardizing the carbureter the temperature of the mixturein the carbureter is evidently too high and therefore more fuel needs tobe sprayed into the chamber to increase the difierence. Thumb-screw 4:1is therefore turned in a direction to compress spring 40 and thrustlever arm 31 to the left to overcome somewhat the force exerted by theexpansion of vessel 21 on vessel 22. This opens needle valve 13 andpermits increase spraying and evaporation of the fuel into the mixingchamber thereby reducing the temperature of the mixture or air andvapor. When the predetermined difference of temperatures is secured, thedevice will maintain this difference, whatever may be the temperature ofthe incoming air, and therefore maintain constant the composition of theexplosive mixture. The thermometers are removed and the plugs 46, 47 areinserted to close the openings. It is now evident if throttle valve 11is open wider so as to create a greater de mand on the carbureter,causinga morerapid flow of air through the same, the amount of liquidfuel passing valve 13, just previous to the opening of the throttlevalve, will not be sufli'cient to bring this increased amount of air upto the proper content of combustible vapor. The result is that thetemperature of the mixture passing thermosensitive element 22 riseswhile that passing element 21 remains constant. This'causes element 22and spring 40 to overcome the expansion force of element 21, therebythrusting rod 28 to the left as viewed in Fig. 1, rocking lever arm 31to the left and lifting needle valve 13 to admit more fuel to the mixingchamber. This action continues until'the content of vapor again reachesnormal when the balance is restored between the opposing forces and thepredetermined difference of temperature between the incoming air and outgoing mixture is restored. Owing to the multiplicity of corrugations inthe thermo- 'response to such variations.

through the carbureter. The reverse movement of the throttle 11 toreduce the demand on the carbureter causes element 21 to overcome thecombined action of element 22 and spring 40, and thereby, reduce thesupply of the drawings to substantially equal that of the mixingchamber, while the mouth of the air conduit is somewhat restricted insize where it opens to the atmosphere above element 21. Hence any vacuumwhich may form in the carbureter will exist to an equal degree aroundboth elements 21,22.

It is to be understood that I do not desire to be limited to anyparticular form or size of thermostat nor to the particular location ofthe connections between the same and the fuel supply valve as thelattermay be exterhal to the air conduit.

What I claim is v 1. In a carbureter, a conduit for conducting airsubject to fluctuations of flow, means delivering vaporizable liquidfuel into said incoming air and outgoing mixture of air and vapor andadapted to control said supply means whereby the proportion of vapor toair delivered by the carbureter is maintained constant under varyingdemands on the carbureter.

2. In a carbureter,a conduit for conduct: ing air subject tofluctuations of flow, means delivering vaporizable liquid fuel into saidconduit, thermosensitive means operable by the difference in temperaturebetween the incoming air and outgoing mixture of air and vapor andadapted to control said supply means, and means for regulating saidthermosensitive means whereby a predetermined proportion of vapor andair is delivered by the carbureter under varying demands on thecarbureter.

3. In combination, a carbureter provided with a mixing chamber, anairinduction conduit, and liquid fuel supply means, thermosensitivemeans exposed to the air in said conduit and to the contents of themixing chamber for automatically regulating said supply for maintaininga constant composition of the explosive mixture.

5. In combination, a carbureter provided with a mixing chamber, an airsupply conduit and liquidzfuel supply means, and thermostatic elementsone of which is exposed to the incoming air and one exposed to the'contents of said mixing chamber, non-flexible connections between saidelements, means operated by the differential movements of said elementsto regulate the fuel supply and adjusting means for said last-namedmeans whereby a predetermined proportion of air and fuel is maintainedin the fuel mixture.

6. In combination, a carbureter provided with liquid fuel supply meansand having an air supply conduit and a valved dis charge conduit forconnecting with an -engine cylinder, a collapsible and expansible vesselin said air conduit and a collapsible and expansible vessel in saiddischarge conduit, a non-flexible connection between said vessels andconnecting means between said vessels and supply means for automaticallyregulating said supply means and to control the composition of theexplosive mixture delivered by said carbureter to the engine.

7. In combination, a conduit open to the atmosphere at one end andadapted to open into a combustion chamber at the opposite end, liquidfuel supply means delivering into the conduit intermediate its ends,thermostatic elements one of which is exposed to the incoming air andone exposed to the outgoing air and vapor mixture, a connection betweenthe movable ends of said thermostatic elements, means transmitting themovements of said connection to control the fuel supply means andadjustable resilient means acting in opposition to one of said elements.

8. In combination, a conduit open to the atmosphere at one end andadapted to open into a combustion chamber at the opposite end, a valvecontrolled spray nozzle opening into said conduit delivering vaporizablefuel therein, thermostatic elements one of which is exposed to theincoming air and one to the outgoing air and vapor mixture, meansconnected to the movable ends of said thermostatic elements and to saidvalve and adapted to transmit the resultant movement of said elements tosaid valve for regulating the supply of fuel to said conduit and tomaintain a constant composition of the air and vapor mixture.

9. In combination, a conduit open; to the atmosphere at oneend andadapted f'tq en into a-combustion' chamber at the opposite end, a valvecontrolled spray nozzle vopening into said conduit deliveringvaporizable fuel therein, thermostatic elements one of which is exposedto the incoming air and one to the out-going air and vapor mixture,means connected to the movable ends of said thermostatic elements and tosaid valve and 10. In combination, a carbureter, liquid fuel supplymeans for the same and thermosensitive means subject to changes oftemperature of the fluid passing through' said carbureter associatedwith said supply means and other means associated with the saidthermosensitive means and supply means for adjusting said devicestojautomatically maintain a predetermined composition of the explosivemixture as discharged from the carbureter.

. 11. In combination, a carbureter provided with a mixing chamber, anairinduction conduit and valve-controlled liquid fuel supply. means,thermosensitive means exposed to the air in said conduit and-to the.contents of said mixing chamber and having connections with said valvemeans, and means for ad ustlng said devices whereby a predeterminedcomposition of the explosive mixture is maintained as discharged fromsaid carbureter. I

12. A carbureter comprising a casing in three separable sections in formof a U- shaped conduit, an. annular fuel supply chamber in the basesection surrounding one leg of the conduit and having a valve-controlledspray nozzle opening into said conduit, a collapsible and expansiblevessel having one end supported by a hub in a semicircular bearingformed in the top of the means for introducing vaporizable liquid intosaid conduit, and thermosensitive mea'ns operatedby the difference intemperature between said gas supply and said mixture wall of theintermediate section and means of gas and vapor and controlling saidliquid supply to maintain a constant gas and vapor in said mixture.

14:. In a device for mixing the vapor of a liquid with a gas, means forintroducing proportion of Vaporizable liquid into a stream of gas and Intestimony whereof I have signed this thermosensitive means actuated bythe difspecification in the presence of two subference in temperaturebetween said gas scribing Witnesses.

and mixture for automatically controlling WESTON M. FULTON. 5 the liquidsupply as the flow of said stream Witnesses:

varies to maintain the relative proportions HINES S. MCCOY,

of gas and vapor in the mixture. I C. H. BROWN, Jr.

